Table 2.

Catalytic properties of the recombinant mesaconate CoA-transferase from H. hispanica.

Substratea		Vmax (U mg-1 protein)	Km (mM)	kcat/Km (s-1 mM-1)
Succinyl-CoA (with 10 mM mesaconate)		69.2 ± 2.6	2.8 ± 0.2	17.8
Methylsuccinate	1 mM succinyl-CoA	11.0 ± 0.6	0.6 ± 0.1	12.4
	5 mM succinyl-CoA	36.8 ± 1.7	2.9 ± 0.3	9.1
Mesaconate	1 mM succinyl-CoA	17.0 ± 0.8	1.3 ± 0.2	9.8
	5 mM succinyl-CoA	45.0 ± 2.1	7.1 ± 0.8	4.6
Glutarate	1 mM succinyl-CoA	18.1 ± 0.8	40.9 ± 3.9	0.32
Acrylate	1 mM succinyl-CoA	6.2 ± 0.3	39.3 ± 4.6	0.12

The values shown are mean values ± SD of results from typically three independent measurements. ^aLow activity was found with itaconate (1.65 ± 0.15 U mg^-1 of protein with 1 mM succinyl-CoA and 100 mM itaconate). However, the activity with itaconate did not follow Michaelis–Menten kinetics and increased linearly with increase of itaconate concentration (up to 100 mM). No activity (detection limit ≤ 0.001 U mg^-1) with acetyl-CoA, propionyl-CoA, butyryl-CoA and acetoacetyl-CoA as CoA donor, and methylmalonate, crotonate, acetoacetate, acetate, propionate, butyrate, citrate, (S)- and (R)-citramalate, 2-hydroxyglutarate, citraconate, fumarate, malate and methacrylate as CoA acceptor.